全文获取类型
收费全文 | 281780篇 |
免费 | 17181篇 |
国内免费 | 4694篇 |
专业分类
耳鼻咽喉 | 3073篇 |
儿科学 | 8659篇 |
妇产科学 | 5480篇 |
基础医学 | 32485篇 |
口腔科学 | 7203篇 |
临床医学 | 19379篇 |
内科学 | 46534篇 |
皮肤病学 | 5344篇 |
神经病学 | 18821篇 |
特种医学 | 11485篇 |
外国民族医学 | 1篇 |
外科学 | 36901篇 |
综合类 | 25428篇 |
现状与发展 | 21篇 |
一般理论 | 8篇 |
预防医学 | 20137篇 |
眼科学 | 4440篇 |
药学 | 29223篇 |
55篇 | |
中国医学 | 13150篇 |
肿瘤学 | 15828篇 |
出版年
2023年 | 5415篇 |
2022年 | 9007篇 |
2021年 | 12532篇 |
2020年 | 9792篇 |
2019年 | 16315篇 |
2018年 | 13861篇 |
2017年 | 10310篇 |
2016年 | 7765篇 |
2015年 | 7822篇 |
2014年 | 9146篇 |
2013年 | 11983篇 |
2012年 | 9483篇 |
2011年 | 14589篇 |
2010年 | 7717篇 |
2009年 | 8262篇 |
2008年 | 9827篇 |
2007年 | 10367篇 |
2006年 | 9707篇 |
2005年 | 9573篇 |
2004年 | 8454篇 |
2003年 | 7232篇 |
2002年 | 6483篇 |
2001年 | 6329篇 |
2000年 | 6621篇 |
1999年 | 6316篇 |
1998年 | 5482篇 |
1997年 | 4641篇 |
1996年 | 3685篇 |
1995年 | 2976篇 |
1994年 | 2960篇 |
1993年 | 2337篇 |
1992年 | 2249篇 |
1991年 | 2035篇 |
1990年 | 1875篇 |
1989年 | 1443篇 |
1988年 | 1456篇 |
1987年 | 1200篇 |
1985年 | 3839篇 |
1984年 | 4863篇 |
1983年 | 3502篇 |
1982年 | 3478篇 |
1981年 | 3188篇 |
1980年 | 2869篇 |
1979年 | 2611篇 |
1978年 | 2054篇 |
1977年 | 1786篇 |
1976年 | 1896篇 |
1975年 | 1597篇 |
1974年 | 1398篇 |
1973年 | 1320篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
地高辛素标记的DNA探针快速鉴定产不耐热肠毒素大肠杆菌的研究 总被引:1,自引:0,他引:1
用地高辛素标记的670bP-LT-DNA片段作为探针,用菌落原位杂交法对9株标准参考株进行检测,结果全部相符。对70株从临床分离的菌株也进行菌落原位杂交.并与32-P标记的探针进行比较.结果地高辛素探针的特异性为97.7%,敏感性为100%,符合率为98.6%。从含正常肠道菌的粪便中可以直接检出LT-ETEC而无须经纯培养。定量试验表明本法最低检出量为6CfuLT-ETEC/斑点。整个检测过程短.仅须24~30h。探针的稳定性好,有效期可长达1年。 相似文献
992.
中国食管癌高发区食管原发性腺癌组织病理学研究Ⅰ.食管原发性腺癌的临床病理学分析 总被引:1,自引:0,他引:1
中国食管癌高发区河南省近15年(1980~1994)病理确诊的7364例食管癌中,其中食管原发性腺癌(PEA)239例,占3.25%。通过对239例PEA手术标本(包括早期癌20例,其余为中、晚期癌)切片系统观察,指出中国食管癌高发区PEA主要起源于食管固有腺体的各级导管部分。PEA的病理组织学可分6型:腺导管癌(109例)、腺鳞癌(54例)、腺样囊性癌(29例)、粘液表皮样癌(20例)、基底细胞样癌(15例)、胃型腺癌(12例)。每型的组织图象及预后均各有特点,提示PEA组织学再分型有意义。 相似文献
993.
Early experience with laparoscopic abdominoperineal resection 总被引:4,自引:0,他引:4
Background: Laparoscopic abdominoperineal resection (LAPR) has not been fully evaluated as a technique in the treatment of rectal and
anal cancer or inflammatory bowel disease. The purpose of our study was to evaluate the early experience with laparoscopic
abdominoperineal resection at Washington University Medical Center.
Methods: A prospective analysis was performed on the first 21 patients undergoing the procedure at Washington University Medical Center.
Indications for surgery included rectal cancer (14 patients), anal squamous cell cancer (four patients), inflammatory bowel
disease (two patients), and anal melanoma (one patient).
Results: The procedure was converted to open procedure in four patients (19%). The mean (±SEM) operative time and blood loss for completed
and converted LAPR were 239 ± 11 min and 424 ± 43 ml, respectively. Postoperative hematocrit dropped a mean of 8.3% ± 1.2%
SEM; five patients required blood transfusion (24%). Wound complication occurred in four patients (19%; three perineal, one
trocar site). Bowel function returned after a mean of 3 days, and mean postoperative hospital stay for the completed LAPR
group was 5 days. Mild pain was experienced by 81% of patients (17/21) while 19% (4/21) noted moderate pain, usually of the
perineal wound. The mean duration of patient-controlled analgesia use was 2 days. During the 1–44-month follow-up, six patients
(29%) died from cancer (stage III or IV at operation) and only one patient developed local recurrence in the pelvis (5%).
There were no trocar-site implants of cancer. Furthermore, there was no relationship between prior abdominal operations, the
amount of blood loss, postoperative drop of hematocrit, or blood transfusion requirement and the length of hospitalization
or complication rates.
Conclusion: Laparoscopic abdominoperineal resection is a feasible alternative to the conventional open technique in both cancer and colitis
patients.
Received: 23 April 1996/Accepted: 8 July 1996 相似文献
994.
Laparoscopic cryosurgery for hepatic tumors 总被引:2,自引:0,他引:2
Background: Hepatic cryosurgery has been shown to be a safe technique that may be well suited to a laparoscopic approach.
Methods: The technical feasibility and safety of laparoscopic cryosurgery was explored first in a pig model. Thereafter we performed
the first successful case of laparoscopic hepatic cryosurgery at our institution.
Results: In the animal model, we found that it is possible to safely identify, target, and cryoablate specific lesions in the liver.
Temperature in the peritoneal cavity remained above 35°C, and pathologic examination of the abdominal wall around the cryoprobe
site revealed no damage. We also successfully treated a 62-year-old man with a metastatic colorectal carcinoma deep in the
right lobe of the liver with laparoscopic cryosurgery using a transpleural approach.
Conclusion: We conclude that laparoscopic cryosurgery is feasible for lesions anywhere in the liver. For lesions high on the dome of
the liver, a transpleural approach may provide better access. 相似文献
995.
Verna W. Y. Yiu Robert P. Dluhy Richard P. Lifton Lisa M. Guay-Woodford 《Pediatric nephrology (Berlin, Germany)》1997,11(3):343-346
In evaluating hypertensive children and adolescents, the etiological considerations should include a set of inherited disorders
that share very low plasma renin activity (PRA) as a common feature. In particular among these disorders, glucocorticoid remediable
aldosteronism (GRA) appears to be emerging as an important etiology of hypertension in the pediatric population. We report
the evaluation of a 9-year-old Caucasian girl who presented with severe hypertension and a strong family history of early-onset
hypertension. Her suppressed PRA, her family history, and her failure to respond to conventional antihypertensive therapy
raised GRA as a potential etiology. The diagnosis was confirmed by an elevated ratio of urinary 18-oxotetrahydrocortisol to
urinary tetrahydroaldosterone and genetic testing, which demonstrated the chimeric gene duplication. The molecular pathogenesis
of GRA and the clinical implications are reviewed.
Received May 15, 1996; received in revised form and accepted September 16, 1996 相似文献
996.
Background: Increasingly larger series of laparoscopic fundoplications (LF) are being reported. A well-documented advantage of the laparoscopic
approach is shortened hospital stay. Most centers report typical lengths of stay (LOS) for LF of 2–3 days. Our success with
LF with a LOS of 1 day led to an attempt at performing LF on an ambulatory basis.
Methods: Sixty-one consecutive patients with appropriate criteria for LF underwent surgery at our institution. Patients were counseled
by the authors as to the usual postop course and progression of diet. All patients received preemptive analgesia (PEA) consisting
of perioperative ketorolac and preincisional local infiltration with bupivicaine. Anesthetic management included induction
with propofol, high-dose inhalational anesthetics, minimizing administration of parenteral narcotics, and avoidance of reversal
of neuromuscular blockade. Immediate postop pain management included parenteral ketorolac and oral hydro- or oxycodone. All
patients were given oral fluids and soft solids after transfer from the recovery room to the postoperative observation unit.
Two patients were excluded from ambulatory consideration due to excessive driving distance from our hospital. Another two
were hospitalized for observation after experiencing intraoperative technical problems.
Results: Of 57 patients in whom same-day discharge was attempted, there were three failures requiring overnight hospitalization: All
were due to pain and nausea; one patient also suffered transient urinary retention. There were no adverse outcomes related
to early discharge, and there were no readmissions. One patient returned to the emergency room after delayed development of
urinary retention. Median time from conclusion of operation to discharge was less than 5 h. No patients expressed dissatisfaction
with early discharge on follow-up interview.
Conclusions: LF can be safely performed as an ambulatory procedure. Analgesic and anesthetic management should be tailored to minimize
nausea and provide adequate pain control.
Received: 1 April 1996/Accepted: 29 May 1997 相似文献
997.
颅脑损伤患者伤后细胞免疫功能变化及黄芪的免疫调节作用 总被引:3,自引:0,他引:3
目的:研究颅脑损伤患者伤后细胞免疫功能的变化规律及黄芪对细胞免疫功能的调节作用。方法:73例中、重型颅脑损伤患者随机分为常规治疗组35例和黄芪治疗组38例。对照组10例。采用放射免疫法.双抗体夹心酶联免疫吸附法及碱性磷酸酶法于不同时间检测各组患者细胞免疫学指标,1个月后进行疗效评价,并进行统计学处理。结果:颅脑损伤患者伤后1d IL-2、CD4、CD4/CD8显著下降,SIL-2R及CD8显著升高(P<0.01)。伤后第30天常规组与黄芪组比较IL-2,SIL-2R,CD8、CD4/CD8有显著性差异,CD4无显著性差异。伤后1月两组患者感染发生率、GCS评分、日常生活能力比较有显著性差异(P<0.01)。结论:中、重型颅脑损伤息者伤后存在显著的细胞免疫功能抑制,黄芪可以改善患者细胞免疫功能状态,提高机体抗感染能力.改善预后。 相似文献
998.
999.
阻塞性黄疸:PTC下胆管钳夹活检的技术方法学研究 总被引:1,自引:0,他引:1
目的探索切实可行的胆管病理学检查新途径.资料与方法连续92例阻塞性黄疸患者接受经皮肝穿刺胆管造影(PTC)和经皮肝穿胆管引流(PTCD)治疗.PTCD过程中,影像监测下经皮经肝胆管穿刺,向胆管内引入活检钳对梗阻段钳夹活检,行组织病理学检查.统计学分析用χ2检验或Fisher确切概率计算法,以α=0.05作为检验水准.结果 92例钳夹活检患者90例成功获得组织块,技术成功率97.83%(90/92).钳夹活检敏感性为88.04%,63例胆管癌性恶性肿瘤钳夹活检敏感性较25例非胆管癌性恶性肿瘤高(93.65%比72.00%,P<0.05).结论PTC下胆管钳夹活检操作简单,创伤小,敏感性高,是一种值得推广的胆管病理学诊断新途径. 相似文献
1000.
高血压患者左室舒张功能与左室肥厚的关系及随龄改变 总被引:1,自引:0,他引:1
为探讨原发性高血压 (以下简称高血压 )患者的左室舒张功能和左室肥厚的关系及其随龄改变 ,抽取 1995年 2月至 2 0 0 2年 7月间门诊高血压患者 4 81例为高血压组 ,以同期体检健康者 2 54 3例为对照组 ,年龄 10~ 80岁 ,并将原发性高血压患者分为 3级 ,每级中按性别分 2组。采用惠普 2 50 0彩色多普勒超声诊断系统检测 2组的室间隔厚度、左室后壁厚度、E/A等指标。使用SPSS软件进行统计学处理分析。结果 :高血压和正常对照组相比E/A显著下降 ,室间隔和左室后壁显著增厚 (P <0 .0 1)。 2个组的E/A均随年龄下降 ,而室间隔厚度随年龄增厚 ,且室间隔厚度和E/A呈显著负偏相关 (P <0 .0 1)。在高血压分级组中 ,Ⅰ~Ⅲ级高血压组中男性的室间隔厚度均厚于女性 (均P <0 .0 1) ,Ⅰ、Ⅱ级高血压组中男性的左室后壁厚度厚于女性 (P <0 .0 5,P <0 .0 1) ,Ⅰ级高血压组中女性的E/A低于男性 (P <0 .0 5)。提示 :左室舒张功能随着年龄的增加而降低 ,而且和高血压左室肥厚呈负偏相关关系 ,性别对其也有一定的影响 相似文献